PARALLAX – What is it and Why is it important?

What is Parallax?
Parallax is the apparent movement of the scope’s reticle (cross-hairs) in relation to the target as the shooter moves his eye across the exit pupil of the riflescope. This is caused by the target and the reticle being located in different focal planes.

Why is it Important?
The greater the distance to the target and magnification of the optic, the greater the parallax error becomes. Especially at longer distances, significant sighting error can result if parallax is not removed.

How to Remove Parallax
This Nightforce Tech Tip video quickly shows how to remove parallax on your riflescope.

While keeping the rifle still and looking through the riflescope, a slight nod of the head up and down will quickly determine if parallax is present. To remove parallax, start with the adjustment mechanism on infinity and rotate until the reticle remains stationary in relation to the target regardless of head movement. If parallax has been eliminated, the reticle will remain stationary in relation to the target regardless of eye placement behind the optic.

This Parallax Discussion first appeared in the Nightforce Newsletter. To get other helpful Tech Tips delivered to your mailbox, CLICK HERE to open the Nightforce Newsletter sign-up page.

PARALLAX – What is it and Why is it important?

What is Parallax?
Parallax is the apparent movement of the scope’s reticle (cross-hairs) in relation to the target as the shooter moves his eye across the exit pupil of the riflescope. This is caused by the target and the reticle being located in different focal planes.

Why is it Important?
The greater the distance to the target and magnification of the optic, the greater the parallax error becomes. Especially at longer distances, significant sighting error can result if parallax is not removed.

How to Remove Parallax
This Nightforce Tech Tip video quickly shows how to remove parallax on your riflescope.

While keeping the rifle still and looking through the riflescope, a slight nod of the head up and down will quickly determine if parallax is present. To remove parallax, start with the adjustment mechanism on infinity and rotate until the reticle remains stationary in relation to the target regardless of head movement. If parallax has been eliminated, the reticle will remain stationary in relation to the target regardless of eye placement behind the optic.

This Parallax Discussion first appeared in the Nightforce Newsletter. To get other helpful Tech Tips delivered to your mailbox, CLICK HERE to open the Nightforce Newsletter sign-up page.

Share the post "How to Correct for Parallax — Optics Tip from Nightforce"

Nightforce Optics has just launched a new monthly newsletter. This free, subscription-based digital publication will offer information on optics, target shooting, hunting, and other topics of interest. The debut October issue, released this week, features match reports, tactical shooting hold-over advice, plus a TECH TIP explaining Parallax.

PARALLAX – What is it and Why is it important?

What is Parallax?
Parallax is the apparent movement of the scope’s reticle (cross-hairs) in relation to the target as the shooter moves his eye across the exit pupil of the riflescope. This is caused by the target and the reticle being located in different focal planes.

Why is it Important?
The greater the distance to the target and magnification of the optic, the greater the parallax error becomes. Especially at longer distances, significant sighting error can result if parallax is not removed.

How to Remove Parallax
This Nightforce Tech Tip video quickly shows how to remove parallax on your riflescope.

While keeping the rifle still and looking through the riflescope, a slight nod of the head up and down will quickly determine if parallax is present. To remove parallax, start with the adjustment mechanism on infinity and rotate until the reticle remains stationary in relation to the target regardless of head movement. If parallax has been eliminated, the reticle will remain stationary in relation to the target regardless of eye placement behind the optic.

If you want to subscribe to the Nightforce Newsletter, CLICK HERE to open the Newsletter then click the green “Join Email List” button at the top of the page.

Field Target (FT) and Hunter Field Target (HFT) airgun disciplines are popular outdoor shooting sports that simulate the challenges of hunting small game. One of the unique aspects of FT competition is target range-finding using parallax and optical focus. (HFT is limited to lower power scopes, so this type of range-fiding is not used in HFT.) Range-finding is very important because the pellets shot by FT airguns drop rapidly once they leave the muzzle (pellets can drop roughly 5″ at 50 yards). If you don’t have your scope set to the correct distance, you’ll probably miss the target high or low.

FT competitors employ high-magnification (35-55X) scopes to sight targets placed from 10 to 55 yards (7.3 to 50m in the UK). Because these scopes have very short depth-of-field at high-magnification, the target will be out of focus unless you have the scope focus/parallax control set very precisely. But competitors can use this to their advantage — once the target is precisely focused, you have effectively established its distance from the shooter. FT scopes often have large-diameter wheels on the side parallax control so the focus can be set very precisely. You can then read marks placed on the scope to adjust the amount of elevation need to put the pellet on target.

Nightforce Benchrest Model vs. NXSby Jason Baney, AccurateShooter.com Asst. Editor
Anyone who has considered purchasing a Nightforce scope inevitably asks: “Which one best suits my application — NXS or Benchrest model?” Shooters also ask: “Why is there such a price difference between the NXS and Benchrest (BR) models?” This article compares the features of the two models (NXS and BR), and provides some guidelines for choosing the right Nightforce scope for your needs.

The NXS line is priced a bit higher, costing about 40% more than the comparable Benchrest model. NXS scopes are also a bit more robust, and feature a side parallax adjustment (side-focus), whereas the BR scopes have an adjustable front objective for correcting parallax. Another main difference is click value, as the BR scopes have 1/8 MOA clicks while the NXS scopes currently feature 1/4 MOA clicks. The “zero-stop” feature is something to consider as well, as it is only available on the NXS models and allows the shooter to quickly spin the elevation turret back down to a close range zero, usually 100 yards, without counting clicks.

Click Value: 1/4 MOA vs. 1/8 MOA
The tighter 1/8 MOA click value is generally more desirable for long range shooting as eighth-minute clicks allow the shooter to adjust Point of Impact more precisely than quarter-minute clicks. The 1/4 MOA clicks are worth about 2.6″ at 1000 yards, while a 1/8 MOA click will move your POI only 1.3″ at 1000. It is easy to see why the 1/8 MOA click value may be preferable when trying to dial in on a 3-5 inch X-Ring or 10-Ring. This is one reason why so many F-Classers favor eighth-minute clicks. The F-Class X-ring is just 5″ in diameter.

If you wanted 1/8 MOA clicks, it used to be that you had to choose the Nightforce BR model. That has changed. Nightforce now offers 8-32X and 12-42X NXS models with 1/8 MOA clicks. The 1/8 MOA-click NXS lineup is ideal for those who prefer side-parallax control AND more precise click values. Another consideration regarding click value is the availability of milrad clicks. “Mil” clicks are desirable when the scope has a mildot or MLR reticle, or similar reticle based on a milradian scale. Mil clicks are only available on NXS scopes at this time.

Ruggedness — NXS has the EdgeDurability is not usually an issue with target shooters as the scope will mainly be used in benign environment on a fixed-distance range. So, as long as a scope tracks and performs reliably, most target shooters won’t fret about durability. For those that may use their rifles in a tactical or field situation, or when hunting, the added robustness of the NXS scope may prove quite important. Now the BR scopes are no slouch as far as durability compared to similar scopes, but, in my experience, they cannot take quite the abuse that the NXS scopes can.

Side-Focus Parallax vs. Front Adjustable Objective
As far as the side parallax adjust vs. adjustable objective, this usually boils down to personal preference. The side-focus parallax adjustment NXS model fits one additional focus lens in the scope body — a lens not required in the front-adjusting Benchrest model. According to Nightforce, this one extra lens in the NXS can reduce potential light transmission by 1.0 to 1.5 percent in the NXS compared to the BR model. However, most human eyes will not notice the difference, and overall resolution should be virtually the same. The side-focus NXS models will be much more convenient from a prone position than will the BR scopes as it is not necessary to reach out of position to correct parallax. The BR scopes tend to be more convenient in fixed distance environments like benchrest or F-class, where there tends to be multiple shots at a similar distance, or there is plenty of time to adjust parallax. Compared to the NXS models, the BR scopes use more movement to produce the same amount of parallax adjustment — so you can say the BR offers “finer” adjustment. By contrast, the NXS side-focus delivers a coarser yet quicker adjustment requiring less movement to “dial-in” minimal parallax.

Zero-Stop Feature on NXS OnlyAnother point of consideration is the availability of a “zero-stop.” This is particularly useful in the same situations that the NXS scopes make the most sense. Namely, tactical or field situations where there may be stress combined with longer shots where dialing the turrets is required. The zero stop allows the shooter to set a stop point, usually a 100-yard zero. Then no matter where the turret is positioned in its span of travel, the zero can be quickly re-established by spinning the turret down until it stops at the pre-set zero.

At present, the Zero-stop is available on all Nightforce variable NXS models except the 12-42×56. So you CAN get the zero-stop on the 8-32 NXS, but not the 12-42 NXS.

CONCLUSION
With the new 1/8 MOA NXS models now available, the decision on which Nightforce scope to buy, will come down to focus/parallax adjustment, field hardiness, and price. Though it may still be a hard decision in certain situations, hopefully this discussion has made the decision a bit easier. All in all, Nightforce scopes are a great value and they offer enough choices to satisfy nearly all shooting situations. Nightforce Scopes can be purchased through EuroOptic.com and other Nightforce dealers.

Share the post "Nightforce NXS vs. Benchrest Model — Which is Best for You?"